Here’s what we learned about JGL, Edward Snowden, and the film during the interview.

"When Oliver Stone first offered me this job, first of all, I was just excited. But the next thought I had was, Wait, Edward Snowden? I know I've heard that name. Which one is he again? What did he do, exactly?"

2.It was very important for him to get Snowden's voice right.

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"He does have a very distinct way of talking. I think that’s indicative of a lot about him," Gordon-Levitt said. He ripped audio from Citizenfour, the documentary directed by Laura Poitras about her contact with Edward Snowden under the aforementioned alias, to help him nail the way in which Snowden speaks.

3.While prepping for the film, Gordon-Levitt and Snowden had a four-hour meeting in Moscow.

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"There's a stereotype and a prejudice I think that maybe I was guilty of, that people who are good at computers are socially awkward...and I was wondering would he be that way," Gordon-Levitt said. But, he added, Snowden was “really polite,” “even-keeled,” and “old-fashioned.”

4.He said that the meeting was low-key, but yes, he assumed he was being surveilled.